Summary of Parfit, Chs

Summary of Parfit, Chs. 16-17 John Nolt

Chapter 16: The Non-Identity Problem

Chapter 16's title seems to denote two closely-related ideas:

(1) the fact that the identities of those affected by our choices may be altered by the choices we make (that is, different people may come to exist if we make one choice rather than another), and

(2) the problem of constructing a true moral theory (which Parfit calls Theory X) that is adequate to deal with this fact.

With regard to (1) Parfit argues that a large-scale public policy may in a couple of centuries so change the course of events that no one will exist who would have existed had a different policy been adopted. This follows, Parfit thinks, from: The Time-Dependence Claim: If any particular person had not been conceived within a month of the time when he was in fact conceived, he would in fact never have existed. (351) Of course the fact that policy choices might completely alter a population does not follow from the time-dependence claim alone. Some auxiliary assumptions must be also made about the effects of public policies on human reproduction. Parfit also assumes that one could not have been conceived by parents other than one's actual parents. (This and the time-dependence claim seem questionable only from such unlikely metaphysical standpoints as the doctrine of pre-existence of souls.) These necessary auxiliary assumptions seem plausible.

Parfit next observes that moral choices are of three kinds:

1 The same people will have existed regardless of which action we take (same-people choices)

2 Different people will have existed if we take one action rather than others, but their numbers will have been the same (same-number choices)

3 Different numbers of (different) people will have existed depending on our choice (different-number choices).

Traditional moral thinking usually concerns same-people choices. (This is true even in life-and-death decisions, because even if a person dies as a result of a decision, that person will still have existed.) But moral thinking about future generations usually concerns different-number choices. Same-number choices are an intermediate case. Chapter 16 examines same-number choices as a preliminary to considering different number choices, which are more problematic.

The appropriate moral principles for same-number choices, according to Parfit, are:

The Same Number Quality Claim (Q): If in either of two possible outcomes the same number of people would ever live, it would be worse if those who live are worse off, or have a lower quality of life, than those who would have lived. (360) and The No-Difference View: It makes no difference to the morality of an act whether the same people or different people will have existed if we act otherwise. (367, 369) The No-Difference View can be more fully articulated as follows: If choice C₁ is between outcome A and outcome B happening to the same people and choice C₂ is between outcome A happening to one set of people and outcome B happening to a different set, then there is no moral difference between the choices (outcome A is of equal value in either choice, and so is outcome B).

Q and the No-Difference View, both of which Parfit affirms, conflict with a plausible alternative:

The Person-Affecting View (V): It will be worse if [specific] people [who would exist no matter what we choose] are affected for the worse. (370) I take this to mean: if choice C₁ is between outcome A and outcome B happening to the same people and choice C₂ is between outcome A happening to one set of people and outcome B happening to a different set, and if outcome B is the worst of the two, then B is worse if it results from choice C₁ rather than from choice C₂.

But another interpretation is: If choice C is between outcome A and outcome B and B is worse for some people (who would exist in A) than A is

Parfit illustrates the differences among these views by various hypothetical examples. Among these are:

The example of depletion vs. conservation: Under the policy of depletion the quality of life would be slightly better for everyone for 200 years than under conservation but thereafter it would be considerably worse. Parfit supposes that after 200 years of the policy of depletion an entirely different population will exist than would have if conservation had been the policy. Hence depletion benefits those who live for the first 200 years and is worse for no one who is born later (since without the policy these people would not have existed). It is therefore worse for no one, period. (Nevertheless, Q implies that depletion is wrong. V, by contrast, implies that conservation is wrong because depletion is worse for no one, but conservation is worse for those who live in the first 200 years.)

The example of two medical programs: Two proposed medical programs have identical costs and effects, except that one would cure 1000 already existing fetuses of a handicap, while the other would instead of curing these fetuses prevent the same handicap in 1000 people yet to be conceived. (V implies that the policy which would prevent the handicap is worse, but the No-Difference View implies that these policies are morally equivalent.)

Parfit thinks these examples show that we should accept Q and the No-Difference View and reject V. If so, then we have sound principles for dealing with same-number choices. That is the main point of Chapter 16. Though Parfit's view is intuitively appealing, this is not a conclusive argument. There may be many other ways of justifying one policy over the other in each of these examples.

Parfit does consider one such alternative justification: that depletion is bad not because it lowers the general quality of life but because it violates the rights of future generations. But there are, as he notes, at least two problems with this claim. One is that it is not obvious that future generations have a right to a high quality of life (especially if, as in Parfit's example, their quality of life, even in the depletion scenario, is higher than ours). The second problem is that we can hardly be said to be violating the rights of people by depleting the resources available to them if the only other option (as in Parfit's example) is that they never exist. People's rights cannot, in other words, be violated by a policy to which they owe their (reasonably worthwhile) existence.

Finally, Parfit draws a preliminary conclusion about the desired theory X. Many moral theories evaluate an action as better or worse only insofar as it is better or worse for the people whom it affects. Parfit characterizes such theories as having a person-affecting form (371, 378). Parfit argues that the correct general theory X will not have a person-affecting form. He claims that this conclusion follows from the No-Difference View together with the assumption that to cause to exist is not a benefit. This argument, first developed on pp. 369-371, and summarized at the bottom of p. 378, may be more fully articulated as follows:

(1) It makes no difference to the morality of an act whether the same people or different people will have existed if we act otherwise. (No-Difference View)

(2) Causing to exist is not a benefit.

(3) There is a unique true theory X.

So (4) The true theory X will not have a person-affecting form (i.e., will not consider an action as better or worse only insofar as it is better or worse for the people whom it affects). Unfortunately, the conclusion doesn't follow directly from the stated premises. Yet I think we can make sense of the argument by considering that there are only two ways in which an act A might be better or worse for a person whom it effects: (i) This person would have existed regardless of whether we chose an alternative action, but A is better or worse for her than the alternatives

(ii) This person would never have existed on at least some of the alternatives to A—that is, act A is part of what causes her to exist and is in that sense a benefit to her.

Now if we assume that causing to exist is not a benefit, then the only remaining way in which an act might be better or worse for a person whom it effects is if it is the result of a choice in which this person would have existed regardless of what we chose. Hence (still assuming that causing to exist is not a benefit), any true theory with a person-affecting form will evaluate an act as better or worse only if it is the result of a choice in which the same people would exist regardless of what we choose (same-person choice). Therefore: (P) If causing to exist is not a benefit, then any true theory with a person-affecting form must imply that it makes some difference to the morality of an act whether the same people or different people will have existed if we act otherwise. —for our very ability to evaluate the act morally will depend on whether the same people or different people will have existed if we act otherwise.

If we now add (P) to premises (1)-(3), we obtain a valid argument that I think adequately reflects Parfit's reasoning. Doubt remains, of course, concerning its soundness, for premises (1), (2) and (3) all are questionable.

Chapter 17: The Repugnant Conclusion

This short chapter discusses an anomaly that arises in different-number choices. The problem is that in large populations, each additional person born may lower the quality of life for all (due to overcrowding, competition for limited resources, etc.). But the total quality of life that that additional person enjoys may nevertheless outweigh the total loss of quality of life to everyone else. If so, then (assuming—and this assumption is crucial—that our goal is to maximize total quality of life) it is better for the population to increase, even though that increase may lower everyone's quality of life, even to a level at which it is barely worth living. But this conclusion seems paradoxical and absurd. Parfit therefore calls it The Repugnant Conclusion. The principle that engenders the paradox is:

The Impersonal Total Principle: If other things are equal, the best outcome is the one in which there would be the greatest quantity of whatever makes life worth living. (387) If we take what makes life to be worth living as happiness, this is the classic utilitarian idea of maximizing happiness. What The Repugnant Conclusion is supposed to show is that classical utilitarianism and any other theories that assume the Impersonal Total Principle fail as candidates for Theory X. They fail, specifically, because they imply The Repugnant Conclusion (which is absurd) in certain different-number choices involving population growth.

The paradox results from the fact that in a growing population it is possible for total quality of life to increase while the average quality of life (quality per person) decreases. We might, then, in an effort to escape The Repugnant Conclusion, suppose that it is average quality of life that matters. If so, we might affirm:

The Impersonal Average Principle: If other things are equal, the best outcome is the one in which people's lives go, on average, best. (386) Parfit will later show that this principle too engenders paradox.
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